Ginseng is a globally well-known nourishing tonic. Therefore, extensive studies have been carried out to identify and characterize its constituents as well as its pharmacological actions of the constitutents. These studies have revealed that the ginseng has a variety of thereapeutic effects such as preventing aging process and arteriosclerosis; improving hyperlipemia, diabetes, hypertension, cerebral functions and hepatic functions; antioxidation; antistress; strengthening immune responses; improving antithrombotic effect; protecting cerebral neurons; anticancer effects, etc. Recently, it was reported that red ginseng contains a little amount of Rg3, a ginsenoside having various effects such as relaxation of blood vessels [J. Nat. Prod. 63, 1702(2000)], inhibition of platelet aggregations [Biol. Pharm. Bull. 21, 79(1998), Korean J. Ginseng Sci. 21, 132(1997)], protection of cerebral neurons [J. Neuroscience Res. 53, 426(1998), Neuro Report 9, 226(1998)], while ginsenosides Rg3, Rg5, Rh2, and Rh1 have anticancer activities [Jpn. J. cancer Res. 87, 357(1996), J. cancer Res. Clin. Oncol. 120, 24(1993), Anticancer Res. 17, 1067(1997), Cancer Letters 150, 41(2000), Dietary Anticarcinogenesis and Antimutagenesis 274(2000)].
Fresh ginseng has been customarily processed into white ginseng or red ginseng for long-term storage purpose. It has been also reported that red ginseng, contains trace amount of ginsenosides such as Rg3, Rg5, Rh1, Rh2, and Rh1 as well as maltol not contained in fresh ginseng or white ginseng, thus imparting improved therapeutic effects. There has been also invented an equipment which can prepare red ginseng extract from fresh ginseng or white ginseng (Korea Unexamined Patent Publication No. 10-2001-19628). Additionally, there have been also studies mainly focused on improving pharmaceutical effects by fortifying the aforementioned ginsenosides contained in small amounts in red ginseng.
Recently it was revealed that ‘sun ginseng’, a type of ginseng processed via a novel method, wherein ginseng is heat-treated at a temperature of 120-180° C., a temperature much higher than that used in manufacturing red ginseng, thereby increasing the contents of the pharmaceutically important constituents usually contained in small amounts in conventional red ginseng and also producing new components, can improve existing pharmaceutical effects [J. Natural Products 63, 1702, 2000, Korea Patent No. 192678]. However, this method has a few drawbacks that it requires special equipments such as a high-pressure heater and it also requires a high heat treatment at a temperature higher than those used conventionally thus resulting in carbonization of ginseng, especially in the case of mass production.